This application is entitled to the benefit of and incorporates by reference essential subject matter disclosed in French Patent Application No. 02 10680 filed on Aug. 28, 2002.
The present invention relates to the field of spectacles of the type without a surround, comprising a bridge interconnecting two lenses, and two hinged side arms or xe2x80x9ctemplesxe2x80x9d.
Rimless spectacles are said to be without a surround, or to be xe2x80x9chole-mountedxe2x80x9d when holes are made through the thickness of the lenses for the purpose of fixing them to the frame, and such glasses are becoming more and more widespread. For the technological background, reference can be made to the following documents: WO-A-01/53877; FR-A-2 751 431; EP-A-0 666 490; EP-A-0 718 660; EP-A-0 997 763; WO-A-01/20388; EP-A-1 120 678; EP-A-1 107 042; WO-A-01/06935; EP-A-1 186 935; EP-A-1 164 410; FR-A-2 810 748; WO-A-02/46830; WO-A-02/33474; WO-A-02/29474; and EP-A-1 180 712.
Attention has more recently been paid to spectacles of the type without a surround in which the side arms are mounted to pivot about an axis that is horizontal and oblique.
Thus, document EP-A-0 426 006 describes spectacles comprising lenses secured to a frame including firstly a lens engagement portion, and secondly arms formed by cylindrical rods connected to the engagement portion by angled portions. Thus, each arm pivots around a conical trajectory about the axis of the screw connecting the arm to the angled portion, between a deployed position for the arm which is then perpendicular to the engagement portion, and a folded position for the arm which is then parallel to the engagement portion. The hinge under such circumstances is totally integrated in the arm and in the angled portion. However, such an arrangement relies on having arms and angled portions of relatively large section, and much greater than the section of wire arms, such that that configuration is not applicable to spectacles having a wire frame.
That consideration has led the Applicant to devise another type of spectacles in which the side arms are mounted to pivot about a horizontal axis that is oblique, said side arms being of wire design. Document U.S. Pat. No. 6,428,166 in the name of the Applicant thus describes an arrangement in which each arm has a hinge end shaped as an eyelet occupying a vertical plane intersecting a general longitudinal direction of the arm, and a hinge bearing is fixed to an inside surface of the corresponding lateral zone to receive the eyelet pivotally about an axis that is substantially normal to said inside surface. Under such circumstances, each hinged side arm is mounted to pivot between a deployed position for use and a folded position where it lies against the inside surfaces of the lenses. This makes it possible specifically to obtain a folded position that is very compact, enabling the spectacles to be stored in a case that is flat and slightly curved.
The above-mentioned arrangement described in document U.S. Pat. No. 6,428,166 in the name of the Applicant uses hinge elements which bear directly against the inside surfaces of the lenses, such that the inclination of the oblique pivot axes of the arms depends, in fact, on the radius of curvature of the lenses where the hinge bearings engage them. This is of little importance when such an arrangement is used for making sunglasses without correcting lenses, in which case curved lenses are used of curvature that does not vary. However, that arrangement is less advantageous when it is desired to use it with correcting lenses of curvature that can vary to a large extent depending on the amount of correction required by the user. As an indication, the radius of curvature of lenses in conventional use lies in the range 65 millimeters (mm) to 140 mm. In addition, it is necessary to use very marked curvature of the hinged side arms insofar as the hinge bearings which bear against the inside surfaces of the lenses cannot, as a result, present the slightest lateral offset from said lenses.
An object of the present invention is to devise spectacles of the type without a surround but avoiding the drawbacks and limitations mentioned above.
The invention thus provides spectacles of structure that can be assembled quickly and reliably, regardless of the type of lens involved, while remaining easy to handle when it is desired to cause the hinged side arms to pivot.
The invention achieves these objects and others by providing spectacles of the type without a surround, comprising a bridge interconnecting two lenses, and two hinged side arms, each side arm being mounted to pivot about a horizontal axis that is oblique, between a deployed position for use and a folded position against the inside surfaces of the lenses, the spectacles being remarkable in that each side arm is connected to the corresponding lens via a hinge link of one-piece structure, said link having an inner portion fixed against the inside surface of the lens and prevented from turning relative thereto, and an outer portion offset laterally from said lens, with said side arm being hinged to the back of said outer portion via a terminal eyelet of the side arm.
The use of such a one-piece link considerably simplifies storage and assembly, insofar as it suffices to assemble the side arm onto the corresponding link, and then assemble said link to the corresponding lens.
Preferably, the inner portion of each hinge link is fixed to the corresponding lens by a through screw, turning being prevented by a through finger projecting from said inner portion. In particular, the inner portion may present tapping associated with the through screw whose shank passes through a hole in the lens, and the finger of said inner portion may be received in a lateral notch in said lens. Such an embodiment makes it possible to use a type of machining that is becoming more and more widespread for spectacles of the type without a surround, in which mode of machining a through hole is formed in the vicinity of each side edge of the lens together with an open side notch placed in the vicinity of said hole.
Advantageously, the outer portion of each hinge link presents a rear facet extending in a vertical plane that is oblique, and against which the terminal eyelet of the corresponding side arm is held. In particular, the outer portion presents a cylindrical finger projecting from the rear facet, with the terminal eyelet of the side arm being mounted thereon, said terminal eyelet being held by means of a screw whose shank passes into a tapped hole formed on the axis of said cylindrical finger. In a variant, the outer portion receives a grub screw having threaded ends, and presenting a central portion that is smooth, the grub screw projecting from the rear facet and having the terminal eyelet of the side arm mounted thereon, said terminal eyelet being held in place by a nut screwed onto the free end of said grub screw. The presence of this rear facet on each hinge link makes it possible to guarantee accurate positioning in three dimensions for the terminal eyelet of each side arm.
According to another advantageous characteristic, the rear facet further presents one or two abutment-forming projections for engaging the side arm and serving to define the range over which said side arm can pivot between its deployed position and its folded position. This makes it possible to avoid the presence of an additional part such as a washer, having lugs acting as abutments, thereby enabling the link to continue to be in, the form of a one-piece, unitary structure by integrating the angular abutment system.
Preferably, the outside portion of each hinge link presents a smooth convex front facet. This smooth convex front facet is clearly visible from the front face when looking at the wearer of the spectacles because this portion of the hinge link is offset laterally relative to the outside edge of the lens. This front facet thus also contributes to appearance, and this is important in the field of spectacles.
Also advantageously, the inner portion and the outer portion of each hinge link together form an obtuse-angled bend, and are connected together by a central portion which presents ductility enabling the angular position of said outer portion to be adjusted relative to said inner portion. This enables terminal adjustment to be very accurate as a function of the particular curvature of the correcting lenses concerned.
Also preferably, each hinge link is made as a casting of stainless steel casting, and includes a central portion that has been subjected to annealing treatment.
Finally, advantageously, each side arm is made of titanium wire of section that is preferably flat for the terminal eyelet and its portion adjacent to said eyelet. This makes it possible to have excellent guidance for the terminal eyelet and makes it easy to manipulate the side arms for pivoting purposes.
Other characteristics and advantages of the invention appear more clearly in the light of the following description and the accompanying drawings, relating to a particular embodiment.